Collapsible reinforcement for reinforced concrete construction



W. F. ZABRISKIE. COLLAPSIBLE REINFORCEMENTFOR-REINFORCED CONCRETE CONSTRUCTION.

I APPLICATION .FlL ED MAR. 29, 1919- v I 1 37 990. Patented May 3, 1921.

W22 2 am 1 Za Zrzs Zia UNITED. STATS Arum OFFICE.

WILLIAM F. zABRrsxrE, or DETROIT, MICHIGAN.

COLLAPSIBLE REINFORCEMENT FOR REINFORCED CONCRETE CONSTRUGTIQN'.

Specification of Letters Patent.

Application filed March 29, 1919. Serial No. 286,092

The invention relates to reinforcementsfor concrete construction being more particularly designed for use in the reinforcement of beams and other spans having latera'lly spaced supports. For such constructions the main reinforcing tension member lies adjacent to the lower face of the body, while the shearing stresses are taken care of by upwardly and outwardly inclined members connected at their lower ends with said main member and anchored at their'upper ends near the upper face of the span. It is also desirable to provide auxiliary longitudinal tension members adjacent to the upper face of the span and extending'over the point of support. These auxiliary members should be 'anchored to the shear members, and for proper reinforcement it is desirable that such members should extend'at least one-fourth of the length of the span on each side of the support.

Various constructions of reinforcement have been designed in which the longitudi nal members are permanently attached to the transverse or shear members, but such constructions are bulky and difficult to handlev in shipment. injury in handling, particularly to the transverse members, so that often their efficiency inreinforcing the span is reduced, if not entirely destroyed. To overcome these difiiculties I have devised a construction of collapsible reinforcement which can be materially reduced in lengthand also in width, and the construction is also one in which in the collapsed position the transverse members are effectively protected or shielded from injury.

In the drawings:

Figure 1 is a side elevation showing my improved reinforcement in position ready to be embedded in the concrete, and indicated in dotted lines the body in which it is to be embedded.

Fig. 2 is a similar view of the collapsed member;

.jacent spans.

There is also danger of;

7 bars.

Fig. 3 is an enlarged cross-section showlng in dotted lines the manner of engaging the stirrups for transverse reinforcement with the main members; 7

Fig. 4 is a plan view showing-the rela Patented May 3 tive arrangement of reinforcements for ad- 1 I The main reinforcing members of'my improved constructlon may be formed of tenslon bars of any sultable -cross-sect1on. I

have, however, shown specifically one form of bar which is particularly adapted for the purpose and which consists in a pair of beads connected by a relatively thin web portion and'having the appearance of a dumb-bell. One of such bars, A, is employed' for the main tension member and is of a length slightly greater than the clear span so as to extend into the supports." The auxiliary tension members. B and C are formed of similar bars of lesser length, but which, in the position for embedding, extend atleast for one-fourth the length of the span to which they are attached :and

over and beyond the support preferably one-eighth of the length of the adjacent span.

The transverse'or shear members D are formed ofloops extending between the I main and auxiliary tension members, and

preferably these loops are threaded through apertures in said main and auxiliary bars and have their end portions overlapped and tied, welded or otherwise secured to each other, as lIIdICatGClELtE. This arrangement provides a strong anchorage for the loops upon the main and auxiliary tension bars,

but also permitsof a swinging parallelomovement by which the auxiliary bars may be swung from the position'sh-own ini F ig. 1 to that illustrated in Fig. 2. In Fig. 1 the-loopsvD incline upward and'o-utg ward from the'bar'A to their points ofa't tachment to the bars B and C, said bars being also properly spaced, while in Fig. 2

the bars B and C lie in contact with the bar A and the loops lie adjacent to each other in substantial parallelism also to said It will also be noted that in the col--' During shipment the members of the structure, and particularly the smaller shear members Dare effectively protected from injury and cannot be bent or distorted in anyway. When, however, the reinforcements are placed in position in the structure, the bars B and C are swung upward and outward until they assume the proper relative positions. If the structure contains a series of alincd spans with spaced points of support, the reinforcingmembers will overlap the points of supportand extend one-eighth of the length of the adjacent span, so that for one-eighth of the distance beyond each point of support there will be a double reinforcement with the single bars extending farther'to one-fourth the length of each span. This will produce the best reinforcing eifect with the least amount of metal.

While I have described the construction as using the specific form of bar of dumbbell cross-section, it 'is obvious'that the same combination could be applied to various other forms of tension bars.

What I. clalm as my invention is 1. A reinforcement for concrete construction, comprising a pair of tension bars and being adapted to contact when the structure is collapsed.

2. A reinforcement for concrete construc- I tion, comprising a pair of tension members and a series of cross links or shear members threaded through apertures in said tension members to pivotally engage the same, and

adapted to form with the tension members a collapsible parallelogram construction in which the tension members contact when the construction is in collapsed position.

3. A reinforcement for concrete construction', comprising a pair of tension members, each prov ded w1th a relatively thin web or flange portion, and a series of transverse sides formed by the tension members being in contact when the construction is c0llapsed. v

4. A reinforcement for concrete construction, comprising a pair of longitudinal tension members and transverse loops extending around and upon opposite sides of said bars and through apertures therein, forming a collapsible parallelogram structure in which in the collapsed position the main bars lie in contact with each other and the loops are arranged at the side of said bars without distortion thereof.

5. A reinforcement for concrete construction, comprising a main tension member and an auxiliary tension member of a length to extend substantially one-fourth the length of said main tensionmember and beyond the same for one-eighth the length of the adjacent span, and a series of transversely extending shear members pivotally connected to said main and auxiliary tension members and forming therewith a collapsible parallelogram structure, the auxiliary member being adapted to lie in contact with and be tween the ends of the main tension member when thestructure is collapsed.

6. A reinforcement for concrete construction, comprising a pair of longitudinal tension members and transverse loops that ex tend around upon opposite sides of saidbars and through apertures therein, the resultant parallelogram structure being adapted to collapse until the tension members contact with each other, and the loops being dis' posed to contact substantially throughout their length with adjacent portions of the tension member's forming supports and preventing deformation of the transverse loops when the structure is collapsed.

7. A reinforcement for concrete construction, comprising a pair of tension bars secured in parallel relatlon by a series of transverse links pivoted at the ends thereof bers when the latter are brought into contact by collapsing of the structure.

In testimony whereof I afiix my signature.

WVILLIAM F. ZABRISKI-E'. 

